RNA-Seq of laying chicken shell gland at two time-points of eggshell formation

This study was performed to understand the differential gene expression of the shell gland tissue in relation to two different stages of eggshell formation. Therefore, the main objective of the current study was to acquire a comprehensive picture of the transcriptional changes in the shell gland of brown-egg laying hens at two different time-points of eggshell formation. Transcriptome analysis revealed thousands of DEGs in shell gland of laying chickens at 15 hr relative to 5 hr time-point of eggshell formation. The significantly down-regulated DEGs indicate that the synthesis activities were already initiated in the shell gland when the egg was still forming in the distal magnum or isthmus regions of the oviduct. The DEGs up-regulated at the 15 hr relative to 5 hr time-point reflect the phospholipid activities and synthesis or transport of molecules for the peak period of eggshell formation. The findings in the current study improve our understanding of eggshell formation at molecular level.